"The uploader may be invoked directly by other components to upload files handed off through the command line; or it may be invoked by the scheduler to look in defined folders on the local device and upload all files present there. In this way, ndupload provides a scheduled catch-up service to upload files which the tracker failed to upload, and saved on disk instead. (And it also follows that the absence of the separate ndupload component in the Core deployment and Zero-footprint cases means that there can be no catch-up uploads after a transient failure of uploads by the tracker.)"